3D Secure (3-D Secure)

A security layer in which the cardholder is verified by an additional step on the issuing bank's side during an online card payment. Verification is usually done with a one-time code sent to the phone or an approval in the bank's app, and it ties the transaction to the cardholder.

The purpose of the layer is to prevent a third party who has obtained the card details from completing the transaction. Even if the card number is correct, the payment is not authorised until the verification step on the bank side is passed; this reduces the risk of unauthorised use and links the transaction record to the cardholder.

In some transactions your bank temporarily blocks the amount for authorisation purposes and releases it when the transaction is not completed; this does not mean you were charged twice. On corporate cards, additional verification rules may vary according to the bank's policy. Which security flow is applied at the payment step can be understood from the redirect screen you see on the payment page.

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